If you want to chill in "Soho", then hit the "ORO" place on Sante Fe (Soho side) just before Charcas between Charcas & Güemes.
It's the one with the PFA officer in a bright orange bib on the take standing either right in front of it, next door at the kiosko, or sitting inside the actual cueva taking a break... as people make illegal exchanges right in front of him.